.38 Special out of .357 Magnum

...as the shorter cartridge's bullet "jumps" further than the 357 cartridge's bullet prior to entering the forcing cone of the barrel.
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First of all, the difference in the jump is quite small. The difference in Maximum OverAll Length between the .357Mag and the .38Spl is only 0.004" 0.04". The significant dimensional difference in the two cartridges is the case length difference ( a little over eighth of an inch) which prevents .357Mag ammo from chambering in a .38Spl chamber. BUT, the overall loaded lengths of the two cartridges are very similar with the .357Mag bullets typically seated a little deeper in the cases than the .38spl projectiles are.

So in practice, the bullet jump difference is going to be very small and it's even possible (though, perhaps unlikely) that a particular .38Spl loading with a heavy bullet seated out to maximum length could have a longer overall length (and therefore a shorter jump) than a light bullet loading for the .357Mag with the bullet seated deeply into the case.

Second, I'm curious how a difference in the bullet jump before the rifling engages is supposed to translate into a noticeable difference in point of impact on the target.
 
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Yes the bullets being the same the jump from case, length of .357 cylinder, to lands and lighter charges of powder the impact will be different.
We don't shoot serious competition so we just adjust our hold. Haven't moved the adjustable sights since I've owned my guns.
I reload my .38s so the difference in velocity is not as great as store boughtn.
 
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The main difference in POI is due to the simple fact that recoil begins when the bullet starts to move. The slower (normally) .38 Special bullet takes more time to move through the barrel, meaning the gun recoils more in that time and the bullet hits higher; conversely, the faster .357 Magnum bullet gets out of the barrel faster and hits lower on the target.

When police forces went from .38 Special to .357 Magnum or .38 Special +P+, they found the bullets striking low on the silhouette targets. Some "experts" told the cops that was so the bad guy would be hit where it would really hurt and discourage future crimes.

Jim
 
No. 7 yards, 21 feet with a 6" 357 magnum..... Shooting groups at that distance is meaningless.
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If he's shooting a 1/2 inch ragged hole with a .357 magnum and it opens up to a 2" spread when he switches to .38 special, how can you claim it's "meaningless"?

Obviously, there's something else going on there.

That revolver is capable of 2" groups @ 25 yards.
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I don't see anywhere that anyone questions the mechanics of a Ruger GP 100 w/1 6" barrel being unable to shoot into less than 2", so, why muddy the waters with that?

Shooting @ 7 yards will never indicate what flaws he has in his shooting by looking at a group.
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Sure it can......plenty of real wold instructors can tell a whole lot about things at any range.
Again, and I digress, if the OP is having issues close in, why introduce even more variables - such as wind &/or lighting or whatever - into the picture?
All that does is make things even more difficult to sort out.

The main difference in POI is due to the simple fact that recoil begins when the bullet starts to move. The slower (normally) .38 Special bullet takes more time to move through the barrel, meaning the gun recoils more in that time and the bullet hits higher; conversely, the faster .357 Magnum bullet gets out of the barrel faster and hits lower on the target.
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That is exactly correct. Plus, an 850 fps 158 grain .38 special might well indeed impact a target 2" away from where a fast stepping (>1500 fps) 110 or 125 grain .357 magnum might impact - especially out of a 6" barrel.
But - is that the issue or - is the issue one of the group size opening up?


Perhaps the OP will return and shed some light on it.
 
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Being the greatest revolver shooter who ever lived, I find no difference between a .38 and a .357 and I always hit the X-ring exactly centered.

Even mixing the rounds in the cylinder and not knowing which is which
when I pull the trigger, I can immediately compensate during the dwell
time in the barrel for the differences and adjust my aim accordingly.

I am :cool: .
 
No. 7 yards, 21 feet with a 6" 357 magnum..... Shooting groups at that distance is meaningless.
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Shooting at 7 yards and claiming that the cartridge is throwing off the gun's PoI IS silly and meaningless. It ain't the gun. It's the shooter's perceived recoil that is affecting the "groups" and PoI.
 
Hi Guys,

Thanks for the responses. I've been shooting for over 20 years but I don't shoot the revolver much. I really doubt it is flinching due to perceived recoil since I there really isn't much recoil with a heavy 6" stainless GP100. I'm sure the gun is capable of way better accuracy than I am. I will have to go back with different loads in .357 magnum and .38 special. I will also be more aware of the recoil and try some shots resting off the shooting table.
 
IIRC Colts used to have a somewhat tighter twist-1 in 14"-IIRC-that made for greater accuracy with 38 Specials. Also what bullet weights are you shooting ?
 
@SIGSHR,

I was shooting CCI Blazer 110 grain .357 magnum and the gun was an absolute tack driver with that load. I believe the .38 special load was 130 grain Aguila. I mixed the rounds up so I wasn't expecting one load over the other.

I also have some.357 magnum from Remington (124 grain), some Geco (158 grain), and CCI (158 grain). I guess this warrants another trip to the range. :)
 
Sounds like your GP doesn't like the .38 Special loads you've been feeding it. At 5, 7 and even 10 yds, there shouldn't be more than an inch or so between groups fired with either caliber. Too, you're talking about a spread group, not a change in impact, if I read your OP correctly. Rod
 
even 10 yds, there shouldn't be more than an inch or so between groups fired with either caliber.
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This is what usually happens. Happens so often we accept it as the norm, and even kind of expect and demand it. HOWEVER, some individual guns have a much more drastic change in point of impact with different loads. One never knows, until you shoot them, and when there is a big difference, there's not much to be done, except live with it, and shoot the ammo that is most accurate.

Adjustable sights can often compensate but sometimes the difference is simply too great. Rare, but it does happen, I've seen it.

Around 30 years ago, a friend brought over an SAA clone in .357mag. I forget the name now, sorry. It was nicely made and finished. and it shot like a dream with 158gr @850fps .38 Special. I mean scary accurate, write your name with it accurate at 10yds.

EVERY single .357 mag load we tried (and we tried about half a dozen, with FOUR different shooters), every one shot at least a foot low and left at the same distance.

Every one. No idea why. Never saw another gun that had THAT much difference in point of impact change, but that one, did.

The owner considered sending it off to be "fixed", but decided to keep it as a "38special only" gun, because it did shoot so well with .38s.

Most of the time, a .357 will shoot somewhat better with .357s than .38s, but any individual gun can do just the opposite.
 
@44 AMP,

Thanks for the above post. I feel better knowing others have experienced something similar to what I experienced. That is why I brought up this question in the first place. I will try and go later this week and will report back to you guys.
 
I remember what the late Skeeter Skelton said about .38spl & .357. His working .357 load was 13.5 grains of 2400 under a 158 grains Thompson gc swc. The load was assembled in .38 spl cases and the bullet was seated out and crimped in the lower crimping groove. That load, he wrote, hit the same poi as the wadcutter loads they shot targets with.

I load a similar combo but in .357 cases instead of .38 cases and crimp in the top crimping groove. My load chronographs 1200 fps, which probably is the same velocity range as Skeeter's LEO ammo. This is my everything, day to day load for the .357. If and when the hammer drops, I have the same bullet over 15 grains of 2400 for about 1450 fps. Actual weights of these bullets are in the 160 plus grain range. And they do indeed have the same poi.
 
74A95 said:
The group size opens up or the point of impact changes? Those are two different things.
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I was going to make the exact same statement. If you are comparing loads you need to compare the same grain bullets. A 110 bullet can be vastly different than a 158gr at the same distance, but 158gr or 125gr at seven yards will not be drastically different in my experience as long as you are using the same grain bullet for each caliber. At 25 yds, you will see a substantial difference. The only way to really know is to experiment with your particular gun.
 
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